Only very cold or hot water come out?

Water temperature is either hot or cold and nothing in between

If there is only cold or hot (and no warm water or anything in between) coming out of the unit, it is most likely that the hose is connected in opposite. To troubleshoot, please kindly make sure that the red stripped hose is connected to the hot water pipe and the blue stripped hose to the cold water pipe. Previously, some other customers connected the hose incorrectly and similar issue would happen. Please try to exchange the hose to the pipe and see if this will fix the issue. Second, when you mount the shower panel, please also make sure that the water hose is not kinked or it will hinder the inflow of the water. Please try to un-mount the shower panel, place it on a chair, straighten the hose and see if there is cold water coming out of the unit.